The tensile strength of ice and dust aggregates and its dependence on particle properties

Abstract

The knowledge of the tensile strength of astrophysical dust and ice aggregates is of major importance to understand the early stages of planet formation in our solar system and cometary activity. In this letter, we report on an experimental setup, developed to measure the tensile strength of granular, astrophysical relevant materials, such as water ice and silica aggregates. We found that the tensile strength of aggregates composed of monodisperse silica particles depends on the grain size of the used material and is in a good agreement with the predictions of earlier works. For aggregates consisting of polydisperse water–ice particles, the measured tensile strength is very low compared to the theoretical prediction, which indicates that the specific surface energy of water–ice at low temperatures is lower than previously assumed.